Magnetic guide roller for conveyor belts

ABSTRACT

The guide roller includes a stack of concentric first, second, third, fourth and fifth disk-shaped sections. The first section is sandwiched between the second and third sections and has the same diameter as the second and third sections, to form therewith the hub of the guide roller. The first section is of magnetically conductive material, not permanently magnetized to any appreciable degree. The second and third sections are permanently magnetized in axial direction, with the facing axial pole faces of the second and third sections being of like polarity. The fourth and fifth sections have diameters greater than the diameter of the first, second and third sections, so as to form radially outwardly projecting guide flanges for preventing lateral shifting of a belt travelling around the hub formed by the first, second and third sections. The fourth and fifth sections completely cover the outer axial pole faces of the respective adjoining ones of the second and third sections. The fourth and fifth sections are of magnetically conductive material not permanently magnetized to any appreciable extent. The characteristic feature of the structure is that the portions of the magnetic flux loops extending outside the material of the first through fifth sections are confined almost exclusively to the annular space intermediate the radially outwardly projecting portions of the fourth and fifth sections. As a result, a strong magnetic attractive force will be exerted upon attractable material in this region, but the magnetic flux, being confined to the just-mentioned annular space, will not interfere with the magnetic action of any other magnetic or magnetizable structure in the conveyor belt arrangement.

United States Patent n91 Spodig 1 I Jan. 7, 1975 MAGNETIC GUIDE ROLLER FOR CONVEYOR BELTS [76] Inventor: Heinrich Spodig, Netteberge 84,

4711 Bork/Westfalen, Germany [22] Filed: Feb. 8, 1974 211 App]. No.: 440,705

[30] Foreign Application Priority Data Primary Examiner- Richard A. Schacher Assistant ExaminerJeffrey V. Nase Attorney, Agent, or FirmMichael S. Striker [57] ABSTRACT The guide roller includes a stack of concentric first,

second, third, fourth and fifth disk-shaped sections. The first section is sandwiched between the second and third sections and has the same diameter as the second and third sections, to form therewith the hub of the guide roller. The first section is of magnetically conductive material, not permanently magnetized to any appreciable degree. The second and third sections are permanently magnetized in axial direction, with the facing axial pole faces of the second and third sec tions being of like polarity. The fourth and fifth sections have diameters greater than the diameter of the first, second and third sections, so as to form radially outwardly projecting guide flanges for preventing lateral shifting of a belt travelling around the hub formed by the first, second and third sections. The fourth and fifth sections completely cover the outer axial pole faces of the respective adjoining ones of the second and third sections. The fourth and fifth sections are of magnetically conductive material not permanently magnetized to any appreciable extent. The characteristic feature of the structure is that the portions of the magnetic flux loops extending outside the material of the first through fifth sections are confined almost exclusively to the annular space intermediate the radially outwardly projecting portions of the fourth and fifth sections. As a result, a strong magnetic attractive force will be exerted upon attractable material in this region, but the magnetic flux, being confined to the just-mentioned annular space, will not interfere with the magnetic action of any other magnetic or magnetizable structure in the conveyor belt arrangement.

1 Claim, 3 Drawing Figures MAGNETIC GUIDE ROLLER FOR CONVEYOR BELTS BACKGROUND OF THE INVENTION The invention relates to magnetic guide rollers for magnetic conveyor belt arrangements of the endless type. Conventionally, when material is to be conveyed along one plane two guide rollers for the endless conveyor belt are required, and when material is to be conveyed along more than one plane, three or more guide rollers are required. It is in general desired that there be no magnetic discontinuity or interruption at the point of transition from the stationary magnet system located beneath the conveyor belt to the magnetic guide rollers; in consequence, it is necessary that the polarities of the magnet poles of the stationary magnet system correspond to the polarities of the magnet poles of the guide rollers. Only in this way can it be assured that the goods being conveyed along the plane of the conveyor belt will reach and pass the guide rollers without interference. This is the reason for the need to make the polarities of the stationary magnet system correspond to the polarities of the magnetic guide rollers.

With conveyor belt arrangements of conventional design, use is sometimes made of guide rollers magnetically correlated to the stationary magnet system. However, if the stationary magnet system is modified, a corresponding modification of the magnetic guide rollers is relatively difficult.

SUMMARY OF THE INVENTION It is accordingly'the general object of the invention to provide magnetic guide rollers for conveyor belt arrangements which are not characterized by the abovementioned disadvantages and limitations.

More specifically, it is an object to provide a magnetic guide roller of a construction which overcomes the disadvantageous prior-art need to correlate the polarities of the magnetic guide roller with those of .the stationary magnet system of the conveyor belt arrangement.

According to the invention, it is proposed to construct a magnetic guide roller such that, by reason of its magnetic configuration, it can be employed in conjunction with any stationary magnet system of a conveyor belt arrangement with complete disregard to the polarities of the magnetic guide roller.

In a disclosed exemplary embodiment of the invention, the magnetic guide roller is comprised of two circular axially polarized magnetic disks axially spaced from each other and having facing poles of like polarity, with an intermediate disk of soft iron sandwiched between the two magnetic disks and concentric therewith. The outwardly facing poles of the two magnetic disks are completely covered by two further soft iron disks of larger diameter which project radially beyond the outer periphery of the magnetic disks all around the outer periphery of the magnetic disks. These larger soft iron disks simultaneously serve as the lateral guide flanges of the guide roller. The intermediate soft iron disk is simultaneously polarized by both magnetic disks, and is accordingly doubly strongly polarized. A magnetic force field, most heavily concentrated at the periphery of the intermediate soft iron disk, extends from the intermediate soft iron disk to the outwardly located larger soft iron disks. In this way, the magnetic field is completely concentrated in the annular region intermediate the two outer soft iron disks, while the soft iron disks themselves outside of the just-mentioned annular space are practically unmagnetized.

With the disclosed exemplary embodiment, a conveyor belt is guided on this guide roller between the two outermost soft iron disks of larger diameter. The magnetically attractable material brought by the conveyor belt into this annular region of concentrated magnetic flux is attracted with an increasing force and is transported a distance corresponding to the angle of the guide roller around which the conveyor belt passes.

The disclosed embodiment of the inventive concept accordingly achieves unhindered transport from the stationary magnet system of the conveyor belt arrangement past the magnetic guide roller, and without requiring any correspondence between the polarities of the magnetic guide roller and of the stationary magnetic system. The outer disks of the disclosed guide roller are substantially completely unmagnetized, with a concentrated magnetic field being confined to the aforementioned annular space intermediate the outer soft iron disks. This results in sort of a magnetic suction effect in direction towards the soft iron intermediate disk. As a result, the material conveyed away from the stationary magnet system of the conveyor belt arrangement immediately comes into the region of the spatially confined magnetic field and is further transported by the conveyor belt arrangement, under the influence of an increasing magnetic attractive force.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims; The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENT The guide roller of vFIG. l is comprised of a soft iron intermediate disk 1, and of two adjoining magnet disks 2, 3 permanently magnetized in the axial direction and having facing poles of like polarity. The other pole faces of the magnet disks 2, 3 are completely covered by soft iron outer disks 4, 5 of larger diameter concentric with disks 1, 2, 3. The endless belt 6 of a conveyor belt arrangement travels around the concentric equaldiameter disks 1, 2, 3. The permanent magnet disks 2, 3, and possibly also the soft iron intermediate disk 1, can be covered by a tubular member of magnetically non-conductive material, with in particular the permanent magnet disks 2, 3 being completely closed off from the outside, as if by a housing. This would simultaneously result in an improved rolling surface for the belt 6 to travel on.

With the illustrated construction of the magnetic guide roller, the magnetic field will be most heavily concentrated at the periphery of the soft iron intermediate disk 1, and the magnetic field will be confined in the annular space 7 defined between the projecting annular portions of the outer soft iron disks 4, 5. The magnetically attractable material conveyed by the belt 6 will be attracted by the soft iron intermediate disk 1.

FIG. 2 shows in a top view two such magnetic guide rollers employed in a simple conveyor belt arrangement. The stationary magnet system is located in conventional manner underneath the belt 6. It may for example consist of oppositely magnetically polarized rails 8 and 9 (shown in dash-dot lines), each terminating short of the adjoining guide roller. Although the magnetic guide rollers with their outer soft iron disks 4, are located practically directly in front of the magnetic rails 8, 9, no detrimental magnetic influence exists, because, as a result of the concentration of the magnetic field in the annular space 7, the soft iron disks 4, 5 out side the annular space 7 are practically unmagnetized.

The constituent parts of the magnetically attractable material carried on the belt 6 will be in linear or point contact with the belt 6, in dependence upon the geometrical form of such constituent parts. However, as the magnetically attractable material travels along the region in which the belt 6 contacts the guide roller, all portions of each of the constituent parts of the attractable material will be attracted by the magnetic field. In other words, the magnetically attractable goods will be attracted by the magnetic fields not only at the surface portions thereof in the most direct contact with the magnet poles, but all throughout the spatial extension of such goods.

Depending upon the shape and size of the conveyed goods, for example metal cans or containers, the magnetic pole formed by the soft iron intermediate disk 1 can be extended towards the soft iron outer disks 4, 5. As a result of the thusly shortened distance between disk l and disk 5, and between disk I and disk 4, an especially strong magnetic field is established having a marked effect upon the force with which the conveyed material is attracted. Conveyed material of substantial spatial extension would for example be metal containers or cans. They can either stand on the belt 6 with their bottoms in contact with the belt, or they can be transported lying on their sides. In both cases, the containers enter into the confined magnetic field of the magnetic guide rollers of the invention and, because of the aforedescribed stronger concentration of magnetic force lines, are held in place by a correspondingly stronger magnetic attractive force. This is particularly important if the containers to be transported are not empty, but filled. What is here described with respect to the magnetic attractive force which holds containers or cans, of course applies no less for all other objects of substantial spatial extension.

FIG. 3 depicts an arrangement of three magnetic guide rollers such as shown in FIG. 1. The guide rollers in FIG. 3 are supported on a two-armed support bracket 10, 11, and are adapted to guide a conveyor belt along two different planes, in succession.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a guide roller for a magnetic conveyor belt arrangement, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claim:

1. In a conveyor belt arrangement, a magnetic guide roller for guiding a conveyor belt of the conveyor belt arrangement, comprising, in combination, a stack of concentric first, second, third, fourth and fifth diskshaped sections, said first disk-shaped section being sandwiched between said second and third sections and being of equal diameter as said second and third sections to form therewith a hub of the guide roller, said first section being of magnetically conductive material, and said second and third sections being permanently magnetized in axial direction with facing axial pole faces of said second and third sections being of like polarity, said first, second and third sections being sandwiched between said fourth and fifth sections, and said fourth and fifth sections having diameters greater than the diameter of said first, second and third sections so as to form radially outwardly projecting guide flanges for preventing lateral shifting of a belt travelling around said hub, said fourth and fifth sections completely covering outwardly facing axial pole faces of respective adjoining ones of said second andthird sections and being of magnetically conductive material not permanently magnetized. 

1. In a conveyor belt arrangement, a magnetic guide roller for guiding a conveyor belt of the conveyor belt arrangement, comprising, in combination, a stack of concentric first, second, third, fourth and fifth disk-shaped sections, said first diskshaped section being sandwiched between said second and third sections and being of equal diameter as said second and third sections to form therewith a hub of the guide roller, said first section being of magnetically conductive material, and said second and third sections being permanently magnetized in axial direction with facing axial pole faces of said second and third sections being of like polarity, said first, second and third sections being sandwiched between said fourth and fifth sections, and said fourth and fifth sections having diameters greater than the diameter of said first, second and third sections so as to form radially outwardly projecting guide flanges for preventing lateral shifting of a belt travelling around said hub, said fourth and fifth sections completely covering outwardly facing axial pole faces of respective adjoining ones of said second and third sections and being of magnetically conductive material not permanently magnetized. 